This was my second PyCon and I spoke to a vastly larger group of people than I did when I attend PyCon 2002. While I did say Hello to a number, the one real conversation I had was with Tim Peters. This year I wasn’t the least bit shy about introducing myself and talking to others. I met a number of great people who just happen to be excellent pythonistas. There was Chris and Ted from ChiPy, Alvin from San Francisco, Christian Tismer, Mark Ramm, Michael Foord, Alex, Ben, Doug (nice job on the pycon schedule) and many, many more. I’ll be blogging about a number of these conversations as time goes on.

After listening to the wonderful things being said about SQLAlchemy at PyCon, I wondered if the following idiom could be implemented as a Domain Object with SQLAlchemy.

Often we have legacy data that we have read only access, to which we need to associate additional meta information. Before this has always meant that the application had to be aware of the relationship of the meta data record in the ExoTagging DB and how to map it to the legacy read-only data. If we could map the two into a single Domain Object it would make are apps a lot cleaner. I spoke to Mark Ramm and he believed that it would be possible and in fact it might even be easy although he hadn’t attempted it before.

I call the idiom ExoTagging because it is logically quite like the idea of Tags, except that tags are kept in a table that resides in a database that is separate from the data that is being tagged. Hence Exo-Tag.

Has anyone else already implemented something like this with SQLAlchemy, if so would you mind sharing your experiences?

I believe that it is time to resurrect the Omaha Python Users Group. I attended that Python Advocacy meeting on Day 1 of PyCon and listened to Jeff Rush and then talked to the leader of ChiPy, Chris McAvoy. There is an advocacy open session tonight @9pm after the OLPC show and tell session. I am hoping to work with others there to set up a system to share web resources, mailing list, website, etc between users groups. People should be able to go to the python site and “Find a local users Group”. The users groups could video tape speakers, and then share those videos for use at other user group meetings and for advocacy in general. A central point for available speakers and a centralized place for companies like O’Reilly, to offer products, books, and other give-aways that could be requested and used by the different users groups.

Of late there has been much to do about the crop of Python based web frameworks. Is one superior to another? Currently, I don’t believe so they all have strengths and weaknesses and I could make a good argument for most of them. However, in the midst of this current genesis there are some shining stars that I think are setting the way forward. These stars are not the frameworks themselves but components that are written to be framework agnostic. For example, Paste, WSGI, SQLAlchemy and ToscaWidgets. By supplying these fundamental and highly useful tools, they are empowering the current and future web frameworks.

I think that all of the frameworks should look for commonality that can be shared, that can be improved for the benefit of all. Even if you want to have a full single source stack as opposed to a best of breed stack plugin architectures should be the standard. So advancements can spread between the frameworks.

What about the frameworks? I believe that in the end their will be two major web frameworks, Django and TurboGears/Pylons. Twisted won’t go away and neither will Nevow but they won’t match the popularity of the two majors. However, I firmly believe that all of the frameworks will have similar traits and in time will tend to a center balance point using different toolkits as the “preferred”.

current form widgets vs. toscawidgets — when that time comes, it shouldn’t even cause a bump unless you are using nested forms, — that api will change (for the better)

setting form widgets to default values

Break

Hints:
In Controllers: Just inherit from controllers in your nested controllers, don’t use controllers.RootController everywhere otherwise you’ll end up with name space collisions and CP won’t behave as expected.

SQLAlchemy

ActiveMapper – SQLAlchemy splits the logical definition from the physical so you can map a logical def back to a backend(s) of your choice (like a legacy db) It implements the “data mapper” method, Domain objects/ mapping layer/ physical data. It has a session mapper that keeps a link between the logical and physical, keeps the identity mapped to the underlying db, plus it caches.

Authentication
TurboGears includes the Identity module. It uses a simple db back end but that can be changed out to an LDAP if desired. There exists an SO provider and an SA provider. There is a page on the old trac, it might be in RoughDocs by now. There is an AD backend too. The LDAP and AD providers only do Authentication, Authorization is handled by the a db local to the app.

Sites Using TurboGearsSessions
There is a CherryPy (CP) session filter that you just turn on. In the .ini files — dev or app, etc
3 backends: file, memory, postgresql
In the future it will be the CP session Tool instead of Filter
CherryPy.????? is a great place to put thread local stuff

Performance and Filters: Cache Filters – is CP deprecating it? Will CP make it a Tool, or if it is more WSGI friendly, will it turn to beaker?

mark.ramm@gmail.com

MochiKit
Is the most under appreciated js package. Mark prefers it to prototype.js. Bob Ippolito json — mochikit. Is tested on ie, ff and the mac browser — is tested hard. Javascript that Doesn’t make you want to shoot yourself in the head. It has a version of the script.acoul.us but uses mochikit instead of prototype. Bob is said to be a testing task master.

hint:
Don’t get caught in the DOM scripting cess pool. 2 secs to download and 20 secs to render. That is bad. DOM scripting is not evil but too much of it is.